Pentaiga are large landscape paintings drawn directly on the walls of a sento bathhouse. A composition centered on Mount Fuji is the standard, and it is widely recognized as the classic view symbolizing the sento bathhouse.

Their origin is said to be Kikaiyu, a bathhouse in Kanda-Sarugakucho, Tokyo, in 1912, and from there the style spread to sento across Japan. Unlike gallery paintings, they are designed to be viewed by bathers looking up from the tub, which is one of their defining features.

This article explains what pentaiga are, why Mount Fuji appears so often, their surprising link to advertising, the rare work of painters who repaint them in a short time, what makes them fun to look at, and how they have changed in modern times. The retro culture of sento as a whole, including the miyazukuri exterior style, the bath attendant counter, and Kerorin tubs, is covered in Retro Sento and Showa-Era Bathhouse Architecture.

What Are Pentaiga?

Pentaiga are large background paintings drawn directly on the walls of a sento bathhouse using oil-based paint. In many cases, they cover the entire wide wall at the far end of the men's bath or women's bath, placed where bathers can look up at them from the tub.

Their role is not limited to decoration. Because bathhouses tend to be enclosed spaces with few windows, painting distant mountains or the sea across the wall creates a sense of openness and visual expansion. The common composition of Mount Fuji with sky and water in front of it is also tied to the practical need to make depth feel more natural.

It is also important to note that this is a different tradition from tiled murals made from fired ceramic panels. Pentaiga are painted directly on the wall, so they can be repainted, while tile murals are fixed as ceramics. Even though both are bathhouse wall art, their materials and methods are entirely different.

Why Is Mount Fuji So Common?

Several reasons explain why Mount Fuji appears so overwhelmingly often in sento pentaiga.

First, Mount Fuji is an instantly recognizable image of Japan. Second, its simple ridgeline is easy to read even from afar, so it looks striking when painted large on a steamy bathhouse wall. Third, it has long been regarded as an auspicious subject and has been favored as a celebratory motif.

Historical background also played a major role. According to tradition, the first Mount Fuji mural at Kikaiyu was inspired by the painter's hometown of Shizuoka. When that first mural became popular, other bathhouses followed suit, and Mount Fuji became the standard subject. The familiar composition of Mount Fuji combined with the sea, a lake, or pine trees is a style that has been passed down in this way.

That said, claims that other subjects should be avoided, such as the idea that a red Mount Fuji or a sunset is disliked because it suggests fire, are only unverified theories. In fact, examples of red Mount Fuji and sunset scenes do exist, so it is not appropriate to treat such ideas as firm rules.

The Link Between Pentaiga and Advertising

The rapid spread of Mount Fuji pentaiga across Japan is said to have been helped by an unexpected mechanism: advertising.

It is said that businesses that noticed the popularity of these background paintings created a system in which, instead of paying for an advertisement at the bottom or around the mural, they covered the cost of the painting through ad fees. Bathhouses could display impressive art with less financial burden, while advertisers could place promotions where they would be seen by many people after bathing. Because these interests aligned, pentaiga spread in close connection with the advertising business.

For that reason, placing the mural where bathers naturally look, with advertisements arranged below it, became one of the defining features of pentaiga culture. Today many murals no longer include ads, but traces of the era when art and advertising were integrated can still be seen in bathhouses across Japan.

The Painter's Work and Its Rarity

Pentaiga are painted by specialist background artists, known as sento painters. Their defining feature is the way they repaint murals without forcing the bathhouse to close for long.

Because a sento is expected to operate every day, repainting is done during limited hours on a closing day or before opening. Painters set up scaffolding and, with almost no preliminary sketching, use rollers and brushes to paint the sky, mountains, and water surface in one rapid sequence. Finishing a large wall in a short time requires careful planning and speed based on a clear mental image of the composition. Not only the finished mural itself, but also this process of repainting while the bathhouse keeps operating, is at the core of a sento painter's skill.

Today, only a very small number of painters continue this work full-time. There were once said to be several dozen, but as the number of sento has declined, demand has shrunk as well. In Tokyo, names such as Kiyoto Maruyama, Morio Nakajima, and Mizuki Tanaka are well known. Because the number of practitioners is so limited, the cultural value of being able to see traditional pentaiga still in active use is increasingly recognized.

What Makes Them Fun to Look At

Pentaiga are designed to be viewed while bathing, so they look different from paintings framed in a gallery. A Mount Fuji floating beyond the steam, or the color of the sky descending from a high point on the wall, blends with the bathhouse space and leaves a lasting impression.

Even when the subject is the same Mount Fuji, the colors and composition vary greatly depending on the painter and the bathhouse. Visiting multiple bathhouses reveals those differences. Some bathhouses also divide the artwork between the men's and women's baths, so the scene on the wall you enter becomes one of the pleasures of the visit.

To make it easier to notice the differences, here is a simple guide to what to look for.

Some bathhouses have newly renovated changing rooms or exteriors but still preserve a traditional mural in the bathing area. That contrast between old and new is part of the appeal of pentaiga.

Please note that photography is prohibited in most bathhouse bathing areas. Even when the mural is worth seeing, the basic rule is to keep it in memory rather than in a photo.

How Things Are Changing Today

The situation around pentaiga has changed significantly in recent years.

First, more bathhouses no longer have pentaiga at all. During renovations, some choose not to install a mural, while others switch to tile murals or modern wall art. Mount Fuji is not the only correct choice; the way bathing spaces are expressed has become more diverse from one bathhouse to another.

Second, there are also new developments within pentaiga itself. A small number of painters are preserving the traditional Mount Fuji composition while incorporating scenery from the local area or even characters into their work. Some have also been commissioned for advertisements, and there are more opportunities for pentaiga techniques to be introduced outside the sento world.

Here is a summary of the differences between pentaiga, tile murals, and modern wall art.

Sento that still feature traditional pentaiga are now drawing attention as cultural highlights amid this diversification. The movement toward modernized sento is covered in The Modern Form of Sento, and the culture of onsen-equipped sento in Tokyo is covered in Tokyo Onsen Sento Culture.

Frequently Asked Questions

Why are there so many Mount Fuji paintings in sento?

The reasons include that Mount Fuji is a clear and iconic image of Japan, its ridgeline is simple and easy to recognize from a distance, and it has long been considered auspicious. In addition, the historical origin story matters: the first Mount Fuji mural at Kikaiyu became popular and then spread nationwide.

Who paints pentaiga?

They are painted by specialist background artists, known as sento painters. Their hallmark is repainting an entire wall in a short time, often before opening, without closing the bathhouse for long. Only a very small number of painters continue this work full-time today, and names such as Kiyoto Maruyama, Morio Nakajima, and Mizuki Tanaka are well known in Tokyo.

Since when have pentaiga been painted?

They are said to have originated in 1912, when Kikaiyu, a bathhouse in Kanda-Sarugakucho, Tokyo, displayed a background painting on the bathhouse wall. The first work is said to have been a Mount Fuji painting inspired by the painter's hometown, and from there the style spread to bathhouses across Japan.

Can I take photos of pentaiga?

In many bathhouses, photography in the bathing area is prohibited. This is to prevent other users from being captured in the image, and even when only the pentaiga are concerned, it is generally best to avoid taking photos inside the bath area. Rules vary by facility, so please follow posted notices and staff guidance.

Are the murals different in the men's and women's baths?

Some bathhouses use different designs, while others create one continuous composition across both sides. In some cases, the men's and women's baths feature different scenery, so part of the fun is seeing what kind of mural appears on the wall of the bath you entered.

Conclusion

Pentaiga are large landscape paintings on the walls of sento bathhouses, and a composition centered on Mount Fuji is their symbol. They originated at Kikaiyu in 1912 and spread nationwide through a combination of clear imagery, auspicious meaning, and a system linked to advertising. They were supported by painters who could repaint them in a short time without stopping operations, but today only a very small number of such artists remain.

In recent years, more bathhouses have adopted tile murals or modern wall art instead of pentaiga, and bathing spaces have become more diverse. Within that diversity, traditional pentaiga still in active use have become even more valuable as cultural highlights. When visiting a sento, looking at the mural while bathing lets you feel what makes that bathhouse unique. For the basics of how to use a sento, see How to Enjoy a Sento, and for the difference between onsen and sento in terms of system and regulation, see The Difference Between Onsen and Sento.

Sources

• Chiyoda City, "Memory Preservation Plate Guide: The First Pentaiga in a Bathhouse"
• Tokyo Bathhouse Association (Tokyo Sento), "I Am a Sento Pentaiga Painter" by Mizuki Tanaka
• Tokyo Bathhouse Association (Tokyo Sento Map), "Pentaiga"
• nippon.com, "The Job of a Sento Painter: Mizuki Tanaka"